1. Field of the Invention
The present invention relates to a method of punching a damper to be attached to an objective part of, for example, a head suspension of a hard disk, to a punching apparatus for the method and to an attaching apparatus with the punching apparatus.
2. Description of the Related Art
A hard disk drive has a disk and a head suspension for supporting a head. The head suspension allows the head to slightly float from the disk to read/write signals when the disk rotates at high speed. In such head suspension, data errors occur due to off tracks that are generated by turbulence (wind excitation), a natural vibration or the like at the time of the rotation of the disc.
To solve this problem, JP2001-067635A discloses a vibration damping technique that attaches a damper to a head suspension, the damper including a viscoelastic body layer and a constraint layer laminated on the viscoelastic body layer.
When the damper is attached to the head suspension, a damper material is prepared on an exfoliative member such as exfoliate paper that is attached on the viscoelastic body layer side of the damper material in advance. Then, the damper is punched out from the damper material to have a required shape one after another. The punched dampers are once aligned on a liner, and an attaching apparatus or a worker with a pair of tweezers etc automatically or manually picks them up to attach or stick on required parts on the head suspensions, respectively.
In this technique, the punched dampers must be aligned between the punching operation and the attaching operation, to deteriorate productivity of the head suspension. Not only that, the dampers may scatter when picking them up from the liner.
JP2009-067635A discloses that a hollow punch punches a damper out from a damper material that is prepared on an exfoliative member as mentioned above, to simultaneously hold the punched damper on a hollow inner surface thereof. The held damper is extruded from the punch to be attached on an objective part of a head suspension. This technique concatenates the punching operation and the attaching operation to improve productivity of the head suspension.
However, recent dampers vary in size according to different requirements of products (head suspensions). If a damper increase in size relative to a conventional damper, the larger damper is attached to the exfoliative member with a large attaching force. The large attaching force may be greater than a holding force of the hollow inner surface to hold the punched damper. This results in a holding error or an inability to hold the large damper.